1. Field of the Invention
The present invention relates to a preventive method against apposition of a marine organism such as a mussel, an oyster and a barnacle, and to a preventive sheet against apposition of a marine organism, which is adapted to be used by being attached to such as the bottom surfaces and the like of a watercraft, a ship, a structure such as a water suction pipe and a water discharge pipe both submerged in water, a storage tank for crude oil, LPG and so on floating in water, an oil fence, a floating buoy, a marine buoy and so on.
2. Prior Art
Conventionally, in order to reduce the harmful influence of apposition of a shellfish such as a mussel, an oyster and a barnacle on a water suction pipe or a water discharge pipe provided in a structure used below water or in contact with the water and on a bottom surface of a buoy or a ship, various preventive methods have been studied.
One known preventive method against apposition of a shellfish is referred to as "a corrugated copper pipe". This is adapted to generate copper ions in the sea in order to kill larvae of shellfish. There is a problem associated with this method, however, in that the sea water itself becomes polluted with copper ions.
Accordingly, almost always a man dives into the sea to remove the shellfish from the above-mentioned submerged object at the right time when the apposite shellfishes are grown to a fair amount. Since manual removal is laborious and troublesome and the operations of plants and facilities must be stopped during the removal work, the workman is in danger, and operating efficiency is bad.